Actually, we need to tell them, the Russians and the Chinese that if any country does this to us, they ALL get a full scale response that destroys them as viable nations. Very much like the unannounced Russian doomsday plan in Dr. Strangelove, except we announce it. That, plus we harden up our infrastructure and put away reserves of food, etc., and also indicate our eagerness (not willingness) to work together to avoid this happening to any nation. Big carrot, big stick - and the incentive will work to reduce the likelihood of this in particular, and tensions in general. A strong and firm, but not aggressive, US is a force for great stability.
I will buy that just so all the countries are on the same page it will be in no countries best interest if a nuke slips out. Also maybe the rogue states will get reined in.